The present invention relates to a prober for testing components, which prober comprises a lower frame, over which a probe holder plate is disposed at a distance therefrom for receiving test probes that make contact with the components to be tested. A displacement device, on which a substrate carrier is disposed in the space between the frame and the probe holder plate, is connected to the frame. The probe holder plate is provided with an opening, below which the substrate carrier can be displaced.
Probers of this type are used for testing components such as semiconductor chips in a wafer package. The semiconductor wafer is placed on the substrate carrier and clamped on the latter. The semiconductor wafer clamped in this way is tested chip by chip by making contact with contact pads present on the chip, applying measurement signals to them, and measuring or determining their reaction to these measurement signals. Test probes are provided for making contact with the contact pads. These test probes are pre-assembled before the actual test procedure. In principle, there are two alternatives for arranging the test probes.
According to the first alternative, the test probes can be designed in the form of test needles, which have associated needle supports, one end of which is then clamped in probe holders. The probe holders are then mounted on the probe holder plate in such a way that the needle points of the test probes corresponding to the pattern of contact pads on the semiconductor chip to be tested penetrate the opening in the probe holder plate.
The second possibility for arranging test probes involves so-called probe cards, in which the needles are already pre-assembled on a card. Corresponding electric conductors and sometimes also electronics, for example, an amplifier, are disposed on this card. The probe card is inserted into the probe holder plate using a probe card adapter in most cases and fixed therein. The needles on the probe card serve for making contact with the contact pads on the semiconductor.
Furthermore, the purpose of use and structure of the prober likewise differ from each other. Thus, for example, so-called vacuum probe systems are known from the prior art in which the components are tested in a vacuum environment. The means for clamping the semiconductor wafer on the substrate carrier must also be designed accordingly. While the substrate carrier can be provided with vacuum clamping devices under normal atmospheric conditions, a vacuum environment requires the provision of other clamping mechanisms, for example, mechanical clamping devices. The basic structure of such vacuum probe systems does not differ from that described above.
Furthermore, it is known from the prior art to expose the components to be tested to defined thermal conditions, for example, heating them up during the testing procedure. For this purpose, the substrate carrier is equipped with a special heating system, which then enables the application of high temperatures to the components to be tested. Naturally, it is also possible to test the components in a lower temperature range, in which case the substrate carrier then ensures a corresponding cooling of the substrate to be tested.
Although these known probers are suitable for testing a plurality of different components, for example, semiconductor chips or so-called MEMs (Micro-Electro-Mechanical components) such as sensors, it has been found that these probers are not suitable for testing magnetic components such as magnetic memory (MRAM-Magnetic Random Access Memory) by way of example, i.e. components, which display a function as a result of magnetic excitation.